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 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.eclipse.imagen.operator;

import java.awt.RenderingHints;
import java.awt.image.RenderedImage;
import org.eclipse.imagen.JAI;
import org.eclipse.imagen.KernelJAI;
import org.eclipse.imagen.OperationDescriptorImpl;
import org.eclipse.imagen.ParameterBlockJAI;
import org.eclipse.imagen.PropertyGenerator;
import org.eclipse.imagen.RenderedOp;
import org.eclipse.imagen.media.util.AreaOpPropertyGenerator;
import org.eclipse.imagen.registry.RenderedRegistryMode;

/**
 * An <code>OperationDescriptor</code> describing the "Dilate" operation.
 *
 * <p>Dilation for gray scale images can be charaterized by "slide, add and max", while for binary images by "slide and
 * set". As always, the kernel is expected to come with a key position.
 *
 * <p>Dilation, unlike convolution and most neighborhood operations, actually can grow the image region. But to conform
 * with other image neighborhood operations, the border pixels are set to 0. For a 3 x 3 kernel with the key point at
 * the center, there will be a pixel wide 0 stripe around the border.
 *
 * <p>When applied to multi-band images the dilation operator processes each band independently using the methodology
 * which would be applied to single band images of the same data type.
 *
 * <p><b> Gray scale dilation</b> is a spatial operation that computes each output sample by adding elements of a kernel
 * to the samples surrounding a particular source sample and taking the maximum. A mathematical expression is:
 *
 * <p>For a kernel K with a key position (xKey,yKey), the dilation of image I at (x,y) is given by:
 *
 * <pre>
 *     max{ I(x-i, y-j) + K(xKey+i, yKey+j): some (i,j) restriction }
 *
 *      where the (i,j) restriction means:
 *      all possible (i,j) so that both I(x-i,y-j) and K(xKey+i, yKey+j)
 *      are defined, that is, these indices are in bounds.
 *
 * </pre>
 *
 * <p>Intuitively in 2D, the kernel is like an umbrella and the key point is the handle. When the handle moves all over
 * the image surface, the upper outbounds of all the umbrella positions is the dilation. Thus if you want the image to
 * dilate in the upper right direction, the following kernel would do with the bold face key position.
 *
 * <p><center>
 *
 * <table border=1>
 * <tr align=center><td>0</td><td>0</td><td>50</td> </tr>
 * <tr align=center><td>0</td><td>50</td><td>0</td> </tr>
 * <tr align=center><td><b>0</b></td><td>0</td><td>0</td> </tr>
 * </table>
 *
 * </center>
 *
 * <p>Note also that zero kernel have effects on the dilation! That is because of the "max" in the add and max process.
 * Thus a 3 x 1 zero kernel with the key position at the bottom of the kernel dilates the image upwards.
 *
 * <p>After the kernel is rotated 180 degrees, Pseudo code for dilation operation is as follows. Of course, you should
 * provide the kernel in its (unrotated) original form. Assuming the kernel K is of size M rows x N cols and the key
 * position is (xKey, yKey).
 *
 * <pre>
 * // gray-scale dilation:
 * for every dst pixel location (x,y){
 *    dst[x][y] = -infinity;
 *    for (i = -xKey; i < M - xKey; i++){
 *       for (j = -yKey; j < N - yKey; j++){
 *          if((x+i, y+j) are in bounds of src &&
 *       (xKey+i, yKey+j) are in bounds of K){
 *             tmp = src[x + i][y + j]+ K[xKey + i][yKey + j];
 *        dst[x][y] = max{tmp, dst[x][y]};
 *          }
 *       }
 *    }
 * }
 * </pre>
 *
 * <p>The kernel cannot be bigger in any dimension than the image data.
 *
 * <p><b>Binary Image Dilation</b> requires the kernel K to be binary, that is, have values 0 or 1 for all kernel
 * entries. Intuitively, starting from dst image being a duplicate of src, binary dilation slides the kernel K to place
 * the key position at every non-zero point (x,y) in src image and set dst positions under ones of K to 1.
 *
 * <p>After the kernel is rotated 180 degrees, the pseudo code for dilation operation is as follows. (Of course, you
 * should provide the kernel in its original unrotated form.)
 *
 * <pre>
 *
 * // binary dilation
 * for every dst pixel location (x,y){
 *    dst[x][y] = src[x][y];
 *    for (i = -xKey; i < M - xKey; i++){
 *       for (j = -yKey; j < N - yKey; j++){
 *         if(src[x+i,y+i]==1 && Key(xKey+i, yKey+j)==1){
 *            dst[x][y] = 1; break;
 *          }
 *       }
 *    }
 * }
 *
 * It should be noted that this operation automatically adds a
 * value of <code>Boolean.TRUE</code> for the
 * <code>JAI.KEY_REPLACE_INDEX_COLOR_MODEL</code> to the given
 * <code>configuration</code> so that the operation is performed
 * on the pixel values instead of being performed on the indices into
 * the color map if the source(s) have an <code>IndexColorModel</code>.
 * This addition will take place only if a value for the
 * <code>JAI.KEY_REPLACE_INDEX_COLOR_MODEL</code> has not already been
 * provided by the user. Note that the <code>configuration</code> Map
 * is cloned before the new hint is added to it. The operation can be
 * smart about the value of the <code>JAI.KEY_REPLACE_INDEX_COLOR_MODEL</code>
 * <code>RenderingHints</code>, i.e. while the default value for the
 * <code>JAI.KEY_REPLACE_INDEX_COLOR_MODEL</code> is
 * <code>Boolean.TRUE</code>, in some cases the operator could set the
 * default.
 *
 * <p><table border=1>
 * <caption>Resource List</caption>
 * <tr><th>Name</th>        <th>Value</th></tr>
 * <tr><td>GlobalName</td>  <td>Dilate</td></tr>
 * <tr><td>LocalName</td>   <td>Dilate</td></tr>
 * <tr><td>Vendor</td>      <td>org.eclipse.imagen.media</td></tr>
 * <tr><td>Description</td> <td>Performs kernel based Dilate on
 *                              an image.</td></tr>
 * <tr><td>DocURL</td>      <td>http://java.sun.com/products/java-media/jai/forD
 * evelopers/jai-apidocs/javax/media/jai/operator/DilateDescriptor.html</td
 * ></tr>
 * <tr><td>Version</td>     <td>1.1</td></tr>
 * <tr><td>arg0Desc</td>    <td>The dilate kernel.</td></tr>
 * </table></p>
 *
 * <p><table border=1>
 * <caption>Parameter List</caption>
 * <tr><th>Name</th>          <th>Class Type</th>
 *                            <th>Default Value</th></tr>
 * <tr><td>kernel</td>        <td>org.eclipse.imagen.KernelJAI</td>
 *                            <td>NO_PARAMETER_DEFAULT</td>
 * </table></p>
 *
 * </pre>
 *
 * <p>Reference: An Introduction to Nonlinear Image Processing, by Edward R. Bougherty and Jaakko Astola, Spie Optical
 * Engineering Press, 1994.
 *
 * @see org.eclipse.imagen.OperationDescriptor
 * @see org.eclipse.imagen.KernelJAI
 * @see org.eclipse.imagen.operator.ErodeDescriptor
 * @since JAI 1.1
 */
public class DilateDescriptor extends OperationDescriptorImpl {

    /**
     * The resource strings that provide the general documentation and specify the parameter list for a Dilate
     * operation.
     */
    private static final String[][] resources = {
        {"GlobalName", "Dilate"},
        {"LocalName", "Dilate"},
        {"Vendor", "org.eclipse.imagen.media"},
        {"Description", JaiI18N.getString("DilateDescriptor0")},
        {
            "DocURL",
            "http://java.sun.com/products/java-media/jai/forDevelopers/jaiapi/<br>org.eclipse.imagen.operator.DilateDescriptor.html"
        },
        {"Version", JaiI18N.getString("DescriptorVersion")},
        {"arg0Desc", JaiI18N.getString("DilateDescriptor1")}
    };

    /** The parameter names for the Dilate operation. */
    private static final String[] paramNames = {"kernel"};

    /** The parameter class types for the Dilate operation. */
    private static final Class[] paramClasses = {org.eclipse.imagen.KernelJAI.class};

    /** The parameter default values for the Dilate operation. */
    private static final Object[] paramDefaults = {NO_PARAMETER_DEFAULT};

    /** Constructor. */
    public DilateDescriptor() {
        super(resources, 1, paramClasses, paramNames, paramDefaults);
    }

    /**
     * Returns an array of <code>PropertyGenerators</code> implementing property inheritance for the "Dilate" operation.
     *
     * @return An array of property generators.
     */
    public PropertyGenerator[] getPropertyGenerators() {
        PropertyGenerator[] pg = new PropertyGenerator[1];
        pg[0] = new AreaOpPropertyGenerator();
        return pg;
    }

    /**
     * Performs binary kernel based Dilate operation on the image.
     *
     * <p>Creates a <code>ParameterBlockJAI</code> from all supplied arguments except <code>hints</code> and invokes
     * {@link JAI#create(String,ParameterBlock,RenderingHints)}.
     *
     * @see JAI
     * @see ParameterBlockJAI
     * @see RenderedOp
     * @param source0 <code>RenderedImage</code> source 0.
     * @param kernel The binary convolution kernel.
     * @param hints The <code>RenderingHints</code> to use. May be <code>null</code>.
     * @return The <code>RenderedOp</code> destination.
     * @throws IllegalArgumentException if <code>source0</code> is <code>null</code>.
     * @throws IllegalArgumentException if <code>kernel</code> is <code>null</code>.
     */
    public static RenderedOp create(RenderedImage source0, KernelJAI kernel, RenderingHints hints) {
        ParameterBlockJAI pb = new ParameterBlockJAI("Dilate", RenderedRegistryMode.MODE_NAME);

        pb.setSource("source0", source0);

        pb.setParameter("kernel", kernel);

        return JAI.create("Dilate", pb, hints);
    }
}
